'Suppose I hold a glass of water and I jog it. Water spills out, and you ask me, "Why did water spill out?" The instinctive answer is to say, "Water came out because you jogged it." But there is another correct answer, which is to say, "Water came out because water was what was inside the glass. If there hadn't been water in the glass in the first place, no water would ever have come out of the glass." Sure, it came out because it was jogged. But water came out because water was inside.'
Christopher Ash, Pure Joy, p.86.
